Automatic bomb sight



April 23,.1929- H. o. RUSSELL ET AL 1,710,115

AUTOMATIC BOMB SIGHT Filed April 18. 1922 2 Sheets-Sheet l [A'VENTORS April 1929. H. o. RUSSELL ET AL I 1,710,115

AUTOMATIQ BOMB SIGHT Filed April 18. 1922 2 Sheets-Sheet 2 INVENTOR 3 jJ y w WTTORNE y Patented Apr. 23, 1929.

UNITED STATES PATE T OFFICE.

HERBERT O. RUSSELL, OF DETROIT, MICHIGAN, AND CHARLES L EIGH PAULUS, OF

' DAYTON, OHIO.

nurorra'rro noun sren'r. 1

Application filed April 18, 1922. Serial No. 555,418.

This invention relates to bomb sights,

especially for use in conjunction with an electrically controlled bomb rack.

The ob ect of-the invention is to provide simple and reliable means whereby the instrument when properly adjusted is caused to function automatically by simply follow ing the target beneath with a sighting instrument such as a telescope. In case the aircraft carrying the instrument is flying on a true course which will carry it directly over the target, when a predetermined point is reached in the movement of the sighting instrument, the electric circuit will be closed and the bomb 'or bombs dropped, this being done automatically without any attention on the part of the bomber. In case the machine is not flying in a path which will carry it directly over the target, the circuit will not be closed and therefore the bomb or bombs will not be dropped.

With the above and other objects in view, the invention consists in the novel construction, combination and arrangement herein fully described, illustrated and claimed.

In the accompanying drawings:

Figure 1 is a sideelevation of the instrument.

Figure 2 is an end view thereof.

Figure 3 is a fragmentary section showing the electrical circuit means.

Figure 4 is a fragmentary elevation showing one of the level adjustment screws and 7 back and forth a fulcrum bloek 8relative to a ground speed scale on the plate 8'- a part of the frame.

Figure 5 is a fragmentary view of the universal supporting means for the telescope.

Figure 6 is a planview of the bomb sight partially in section.

In the construction of the automatic bomb sight, we employ a' mounting frame or bracket 1 having end upright portions 2 and 3 in which is journaled a threaded shaft 4 operable by means of a knob 5 at one end thereof used to regulate the instrument in accordance with the ground speed of the aircraft as will hereinafter appear. Surrounding the shaft 4 freely is a rotatable sleeve 6 carrying an operating knob 7 which is manipulated to compensate for altitude, the altitude correction being compounded on the ground speed correction or vice versa.

The threaded shaft 4 engages or moves nected by gears 11 and 12 to a threaded shaft 13 which is perpendicular to the shaft 4 and operatlvely connected to a vertically movable fulcrum block 14 carrying a pin or journal 15.which is movable along a slot or guideway 16 extending longitudinally of the support 10. l

A sightin'g instrument 17 such as a telescope 1s supported by a universal bearing or fulcrum ring .18 which is connected to the support 10 in the manner illustrated in Figures 5' and. 6. This permits the telescope to be moved forwardly and rearwardly and from one side to the other relative to the mounting frame. At its upper end the support 10 18 formed with a rearwardly extending arm 19 having a wide channel 20 therein as shown in Figure 3 which is arranged parallel to or on the fore and aft aims of the ship. A hole 21 extends through the channeled arm 19 of the support 10 at one end of the channel 20 as shown in through said hole and into engagement withanother contact member 24 mounted in insulated relation on the support 10; This closes the circuit which controls the dropping of the bombs in the bomb rack. It will be noted that the channel 20 is wider than the diameter of the pin 23. This is done in order to prevent the dropping of a bomb in case the aircraft is not moving along a path which will lead it directly over the target. In such case the pin 22 will pass .to one side or the other of the hole 21. Only when the aircraft is moving along the proper course will the pin 23 drop through the hole 7 21 and close the bombing circuit. The base of the mounting bracket carries a irit level 25 for'denoting the levelness of t e frame; which is adjusted by means of a screw 26. A lateral arm or extension 27 carries a irit level 28 in right angle relation to the lev 25,

and a level-adjusting screw 29 which passes through a fitting 30 on the craft. The leveladjusting screw 26 passes through another fitting 31 on the aircraft.

The mounting bracket which is provlded with a depending leg 32 which provides a lower bearing for the threaded shaft 13 and a stop for the fulcrum 14. Mounted on the leg 32 is an altitude scale shown at 33 with reference to which the block 14 is adjusted in accordance with variations of altitudes. -In the operation of the instlrumenbt, tle su ort 10 is iven proper an arity y a jud ing the khobs 5 and 7 53 1 the ground speed and altitude corrections respectively,

the one correction being compounded on the other. The settings in both cases are determined by noting the position of the fulcrums with reference to the altitude and ground speed scales. The sighting instrument 17 is then swung to the extreme rearward position to secure the first glimpse of the target at some point on the ground ahead of the ship. As the 'ship' approaches the target the instrument is constantly kept sighted on the target, the pilot meanwhile endeavoring to fly in as nearly a true course over the target as possible. At the proper interval for the release of the bomb denoted by the angularity of the support 10, the bombing circuit will be completed by the contact on the sighting instrument arriving .at the end of the segment 19. If the course of the ship has been roperly maintained in which event the vertlcal plane through the axis of the sighting instrument fixed on the target is in a line. on or parallel to the fore and aft axis of the ship, the contact on the sighting instrument will drop through the opening in the support 10 and complete the bombing circuit. Otherwise the bombing circuit is not completed and the pilot will have to maneuver his ship about and repeat the operation. There .is thus definite assurance when the bomb is released that it will reach the target.

The improved bomb'sight hereinabove de scribed andillustrated inthe drawings removes the personal element from dropping "bombs inasmuch as it is unnecessary to op-- crate any lever or button whenthe ship is at the correct dropping position relative to the target. In case the target should be slightly to the side of the line of flight of the airplane, the circuit closing pin will pass one side of the hole in the channelled arm and will not dro through the hole and will therefore fai to close the circuit. The bombs will therefore not be dropped. The location of the hole in the support makes certain that if the target is kept upon the crosshairs of the telescope the bombs candropped unless the airplane is in the correct position for the bombs to strike the e s The altitude n essary for setting 1. An automatic bomb sight for aircraft,

embodying a mounting frame, a sighting instrument support thereon, a sighting instrument movably supported thereby to be kept constantly on a target, means for varying the angle of said support relative to said frame to compensate for'ground speed, an electrical contact member on said support, and another electrical contact member carried by the sighting instrument, and means to prevent said contact members from engaging except when the movement of said sighting instrument is on a line on or paral lel to the fore and aft axis of the ship and hence when the course of the aircraft is not in a true line with the target, the last named means including a contact pin on the sighting instrument and a channeled portion of said support. parallel to the fore and aft axis of the ship having an opening through which said pin can move in only one osition of the sighting instrument, this position being to close the bomb circuit when the sighting instrument is on a line to the fore and aft axis of the ship thereby insuring that the bomb is dropped only when the aircraft is moving at the instant in a true direction to pass directly over the target.

' 2. An automatic bomb sight for aircraft, embodying a mounting frame, a sighting instrument support, a sighting instrument movably supported thereby, means including two shiftable fulcrums for Varying the angle of said support relative to said mountmg frame to compensate for ground speed and altitude respectively, an electrical contact member on said support, and another electrical contact member carried by the sighting instrument and adapted to engage said first contact when the sight is in a predetermined position relative to its support. 3. In an automatic bomb sight for aircraft,

the combination of a support, a ground 1 speed screw rotatably mounted therein, an

altitude screw rotatably mounted in said crums,

erence to said support, a contact on said instrument movable therewith relative'to said support, and a second contact on said s'u port to be engaged by said first contact 111 only one position which the sighting instrument may occupy with respect to said suport.

p 4. An automatic bomb sight for aircraft comprising the combination with a mounting frame of a sighting instrument support thereon, a universally pivoted sighting instrument'mounted on said support, means for varying the angle of said support relative to said mounting frame to correct for ground speed, a second means for varying the angle of said support to correct for altitilde and electric contact means carried by said sighting instrument and support respectively and adapted to contact when the sighting instrument is in a predetermined position relative to said support.

5. An automatic bomb sight for aircraft comprising the combination with a mounting frame of a sighting instrument support thereon, a universally pivoted sighting instrument mounted on said support, manually operable means for varying the angle of said support relative to said frame to correct for ground speed and-altitude respectively and means operated by the movement of said sighting instrument relative to said support to actuate a controlling circuit when the sighting instrument is moved to a predetermined angle of inclination.

6. An automatic bomb sight for aircraft comprising the combination with a mounting frame of a sighting instrument support thereon, a universally pivoted sighting 1nstrument mounted on said support, an electric contact element carried by said sighting instrument, a second electric contact element on said support and means intermediate said first and second element whereby the swinging of said sighting instrument in a predetermined plane actuates said element.

7. An automatic bomb sight for aircraft comprising the combination with a mounting frame of a sighting instrument support thereon, a universally pivoted sighting instrument. supported thereby and to be kept sighted on a target, a ground speed scale on said support, means comprising a shiftable fulcrum movable relative to said ground speed scale to vary the angle of inclination of said support to correct for ground speed, and electric contact member carried by said sighting instrument and support respectively and adapted to contact one with the other when the sighting instrument is in a predetermined position relative to said support.

8. An automatic bomb sight comprising the combination with a mounting frame of a sighting instrument support thereon, a universally pivoted sighting instrument support thereby to be kept sighted on a target, a ground speed scale on said support, a vertically mounted altitude scale on said support, means comprising a vertically shiftable fulcrum movable in relation to said altitude scale to vary the angle of inclination of said support to correct for altitude, elec tric contact member carried by said instru ment and a second electric contact member on said support, said contact being brought into contact with each other in only one position which the sighting instrument may occupy with respect to said support.

9. An automatic bomb sight for aircraft comprising the combination with a mounting frame of a sighting instrument support.

thereon, universally pivoted sighting instrument supported thereby to be kept sighted on a target, means for varying the angle of said support relative to said mounting frame to correctfor ground speed, a vertically mounted altitude scale on said support, means comprising a vertically shiftable fulcrum movable in relation to said altitude scale to vary the angle of inclination of said support to correct for altitude, said last mentioned correction being compounded on the ground speed correction, an electric contact member on said support, a second contact member carried by said sighting instrument and a channel portion carried by said support and having an opening therein whereby to permit said last mentioned contact member to contact with said first mentioned contact member when said sighting instrument is in a determinate position relative to said support.

In testimony whereof we aflix our signat-ures.

' HERBERT O. RUSSELL.

CHARLES LEIGH PAULUS. 

